We report two cases of self-induced water intoxication with rhabdomyolysis. They had been diagnosed as chronic schizophrenia, and admitted to mental hospitals. The patients were transferred to our emergency room because of sudden loss of consciousness and generalized convulsions. Laboratory findings revealed marked hyponatremia (case 1; 109 mEq/L and case 2; 104 mEq/L). CT scans showed the effacement of interhemispheric and bilateral sylvian fissures and sulci of the cerebral hemisphere due to diffuse brain edema. 10% glycerol and saline were intravenously injected to the patients. They recovered from hyponatremia after excreting a large amount of urine. Their disturbed consciousness recovered to the normal level in parallel with the normalization of their serum sodium concentration. Soon after the normalization of their consciousness level, their serum creatine kinase (CK) was markedly elevated (case 1; 13086 IU/L and case 2; 41832 IU/L), and their serum myoglobin level was also significantly elevated (case 1; 2670 ng/ml and case 2; 1420 ng/ml). A sufficient amount of transfusion was performed for avoiding the acute renal failure. The two patients recovered from rhabdomyolysis without any severe complication. We conclude that brain CT is useful for the diagnosis of brain edema, and monitoring of CK is also important to anticipate renal damage secondary to rhabdomyolysis.